For example, almost all lithium polymer batteries are 3.7V or 4.2V batteries. What this means is that the maximum voltage of the cell is 4.2v and that the "nominal" (average) voltage is 3.7V. As the battery is used, the voltage will drop lower and lower until the minimum which is around 3.0V.
Depending on the design and chemistry of your lithium cell, you may see them sold under different nominal "voltages". For example, almost all lithium polymer batteries are 3.7V or 4.2V batteries. What this means is that the maximum voltage of the cell is 4.2v and that the "nominal" (average) voltage is 3.7V.
When completely charged, the maximum voltage for LiPo (lithium polymer) batteries is typically set at 4.2 volts per cell. Overvoltage can result in shorter battery life and possible safety risks. Fully Charged Voltage: When completely charged, each LiPo cell achieves its maximum voltage of 4.2V.
The following six parameters must be defined at an early stage if design-in is to be successful. The average single cell voltage for lithium polymer cells is 3.6 volts as standard. The switch-off voltage is 3.0 volts and the maximum charging voltage is 4.2 volts. If a higher voltage is required, several cells can be connected in series.
Voltage: The nominal single-cell voltage for Li-polymer cells is 3.6V, on average; the charge cut-off voltage is 3.0V; and the maximum charging voltage is 4.20V. On the market there are also cells with charging voltages of 4.35V and 4.40V. The required voltage should be defined. If a higher voltage is required, a series connection is possible.
The maximum charging voltage is related to the chemical composition and characteristics of the battery. The full charging voltage of a normal lithium battery is 4.2V. There are high voltage LiPo batteries with maximum charging voltages of 4.35V; there are a series of batteries from Grepow that can reach 4.45V for its maximum.